C.R.S. § 18-12-111

(1) Any person who knowingly purchases or otherwise obtains a firearm on behalf of or for transfer to a person who the transferor knows or reasonably should know is ineligible to possess a firearm pursuant to federal or state law commits a class 4 felony. (2) Intentionally left blank —Ed. (a) Any person who is a licensed dealer, as defined in 18 U.S.C. sec. 921 (a)(11), shall post a sign displaying the provisions of subsection (1) of this section in a manner that is easily readable. The person shall post such sign in an area that is visible to the public at each location from which the person sells firearms to the general public. (b) Any person who violates any provision of this subsection (2) commits a civil infraction.